Because of the possible connection between high blood cholesterol and atherosclerosis, many efforts have been made to find ways and substances which would reduce the cholesterol in the mammalian body. One of these ways is to inhibit in mammals the body's ability to synthesize cholesterol.
Recently, Endo et al., described (U.S. Pat. Nos. 4,049,495 and 3,983,140) a fermentation product obtained by cultivation of a microorganism of the genus Penicillium and isolation from the medium. They called it ML2l36B and determined its structure together with two related compounds 236A and 236C. Its structure, under the name compactin, was also determined by A. G. Brown, T. C. Smale, T. J. King, J. Chem. Soc. (Perkin I) 1165 (1975). This compound has been found to be a strong inhibitor in vivo of the biosynthesis of cholesterol.
More recently, Monaghan et al. have reported (U.S. Pat. No. 4,231,938) that a methyl analog (Formula I) is formed by the cultivation of a microfungus of the genus Aspergillus and that this product is an even more potent inhibitor of cholesterol biosynthesis.
From the same fermentation, Albers-Schonberg et. al. (U.S. Pat. No. 4,294,846) isolated the dihydro analog of structure IV. ##STR3##
Also more recently, Endo has reported (J. Antibiotics, August 1979, page l852, and W. German Offenlegungschrift No. 30 06 216), the isolation of a compound identical with Compound I from a cultivation of a strain of Monascus ruber, an entirely different microorganisms.